IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002 
  
  
  
  
   
  
  
   
  
  
  
  
   
  
  
  
  
  
  
SPACE TECHNOLOGY INPUTS FOR PRECISION FARMING 
R. S. Dwivedi®, S. P. Wani®, A. Bhattacharya® and R. R. Navalgund® 
"National Remote Sensing Agency, 
Department of Space, Govt. of India 
Balanagar, HYDERABAD - 500 037 
India 
"International Crops Research Institute for 
Semi-Arid Tropics (ICRISAT) 
PATANCHERU 502 324 
India 
Commission VII, Working Group-VII/2 
KEYWORDS : Variable Rate Technology, GPS, GIS, Decision Support System 
ABSTRACT: 
Applications of agricultural inputs at uniform rates across the field without due regard to in-field variations in soil fertility and crop 
conditions does not yield desirable results in terms of crop yield. The management of in-field variability in soil fertility and crop 
conditions for improving the crop production and minimizing the environmental impact is the core issue of precision farming. 
Thus, the information on spatial variability in soil fertility status and crop conditions is a pre-requisite for adoption of precision 
farming. Space technology including global positioning system (GPS) and GIS holds good promise in deriving information on soil 
attributes and crop yield, and allows monitoring seasonally- variable soil and crop characteristics, namely soil moisture, crop 
phenology, growth, evapotranspiration, nutrient deficiency, crop disease, and weed and insect infestation, which, in turn, help in 
optimizing inputs and maximizing crop yield and income. Though widely adopted in developed countries, the adoption of precision 
farming in India is yet to take a firm ground primarily due to its unique pattern of land holdings, poor infrastructure, lack of 
farmers ability to take risk, and socio-economic and demographic conditions. The article introspects the scope of precision farming 
under Indian conditions and the possible role that space technology can play in this endeavour. 
1.0 INTRODUCTION 
Green revolution has played a vital role in boosting the 
agricultural production in India since its inception in 1970. 
The annual food grain production which was only 109 million 
tonnes in 1970, had risen to 196.13 million tonnes in 2000- 
2001. However, while striving for improved agricultural 
production, due emphasis has not been laid on soil and 
environmental health. Excessive use of fertilizers, insecticides 
and pesticides, and lack of organic manure which promote soil 
biota, has led to pollution of groundwater and depletion of the 
population of actinomycetes which provide protection to plant 
against diseases. As a result, crop production though increased 
initially, has exhibited either stagnation or declining trend after 
mid-eighties. The improvement in agricultural production on a 
sustained basis while maintaining soil and environmental 
health calls for optimal utilization of agricultural inputs based 
on crops demand. 
Hitherto, farmers have been applying fertilizers based on 
recommendations emanating from research and field trials 
under specific agro-climatic conditions, which have been 
extrapolated to a regional level. Since soil nutrient 
characteristics vary not only between regions and between 
farms but also from plot to plot (Ladha et al., 2000), and within 
a field or plot, there is a need to take into account such 
variability while applying fertilizers to a particular crop. 
Consideration of in-field/plot variations in soil fertility and 
crop conditions and matching the agricultural inputs like seed, 
fertilizer, irrigation, insecticide, pesticide, etc. in order to 
optimize the input or maximizing the crop yield from a given 
     
quantum of input, is referred to as precision farming or 
precision agriculture or precision crop management. 
2.0 THE INDIAN SCENARIO 
In India, broadly two types of agriculture viz., high input 
agriculture characterized by the provision of assured irrigation 
and other agricultural inputs, and subsistence farming which is 
confined mostly to rain-fed or dry land regions, are prevalent. 
Nearly two-third arable land in India are rain-fed. The 
crop yields are very low (=1 t ha!) and very good 
potential exists for increasing productivity of rain-fed 
cropping systems. For instance, soybean is grown in Central 
India which is considered as heartland of rain-fed agriculture, 
and its average productivity is 1 t ha’. Recent studies at 
ICRISAT using crop growth simulation model have 
demonstrated that the potential yield of soybean could be 
achieved upto 3.05 t ha”, and the yield gap of 1.6 to 1.8t ha” 
exists which could be minimized and productivity could be 
increased substantially under rain-fed conditions by adopting 
improved soil, water, and crop management practices (Singh 
et al.,2002). In another study which was carried out at Adarsha 
watershed, Shankarpally mandal (an administrative unit) in 
Ranga Reddy district of Andhra Pradesh, southern India, 
farmers have increased their farm productivity by 2 to 3 times 
(maize yield 3.3 to 3.8 t ha'') as compared with baseline yields 
(1.5t ha), increased incomes (3.5 times) with maize/ 
pigeonpea system as compared to the traditional cotton system, 
reduced runoff (6% vs 12%) and soil loss (0.385 vs. 0.984 t 
ha-1), improved groundwater levels, increased vegetation 
cover (200 ha vs. 129 ha) and diversified the system by 
adopting this approach (Wani et al., 2002). 
    
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